Mixing slurry



June 8 1926.

1,587,533 P. T. LiNDHARD MIXING SLURRY Filed August 2 1924 2 Sheets-Shet 1 INVENTOR June 8 1926.

. I 1,587,533 P. T. ,LINDHARD MIXING SLURRY Filed August 2} 1924 2 Sheets-Sheet 2 INVENTOH iii Patented June 8, 1926,.

PATENT "orricE.

IPOVL 'I. LINDI-IARD, OF BROOKLYN, NEW' YORK, ASSIGNOR 'IO F. L. SMITH & 00., OF NEW YORK, N. Y., A GOBPORATION OF NEW JERSEY.

MIXING SLURRY.

Application filed August 2, 1924.

It is well known that in the manufacture of Portland cement by the wet process the semi-liquid mass of finely divided cement raw materials in water, known as slurry, as it comes from the grinding mill, only approximates the proper composition, and must be corrected as to its composition before it is delivered to the kiln. For this reason the slurry, as it comes from the grinders, is commonly discharged into receiving tanks, in some of which the slurry may be high in line while in others it is low in line. When the chemical composition of the slurry in the receiving tanks has been determined by analysis it is transferred from the several tanks in such proportions as may be indicated by analysis to a mixing tank where the thorough mixture of the slurry is effected and the proper composition is at tained. From the mixing tank the slurry is sometimes delivered directly to the kilns and is sometimes delivered to storage tanks from which it is delivered to the kilns as required. The object of the present invention is to eliminate as far as possible the considerable amount of pumping which has been neces sary heretofore and thereby to reduce the expense of handling, while at the same time providing a maximum amount of material in readiness for transfer to the kilns. The invention will be more fully explained hereinafter with reference to the accompanying drawings in which it is illustrated and in which Figure 1 is a top view of apparatus in which the mixing and storing of slurry may be carried on in accordance with this invention.

Figure 2 is a transverse section indicated .by the broken line 22 of Figure 1.

Figure 3 is a transverse section of the Jlane indicated by the broken line of Figure 1.

From the grinder or other source of supply the slurry may be delivered through a pipe at to a box Z) from which it is distributed through launders c to several receiving tanks d, each of which is equipped with a suitable agitating device or stirrer d. As shown the several stirring devices may be driven through gearing d from a common shaft (i operated by a motor indicated at (Z From the several receiving tanks OZ, through pipe connections d which are pro- Serial No. 729,695.

vided with control valves 6Z6, the slurry, when the composition in the several receiv ing tanks has been determined by analysis, is delivered by gravity to a mixing tank 6, in such proportions from the several tanks d as may be necessary to secure the correct composition in the mixing tank 6. The latter is placed at a lower level than the receiving tank 0? so that the slurry may flow by gravity from the bottom of each of the tanks d into the mixing tank 6 at or near its. top. The mixing tank is provided with suitable stirrers or agitating devices, one of which is shown at e in Figure 3, and the several stirre-rs may be driven through gearing e and a common shaft 6 from a motor indicated at e*.

From the mixing tank 6 the slurry is delivered by gravity into the storage tank f and in order that the slurry may be delivered from the bottom of the mixing tank, where the mixture is most thorough, into the storage tank f and yet may be delivered from the mixing tank only when the mixing tank e is completely filled, that is that it shall overflow from the mixing tank and the mixing tank therefore remain completely filled throughout the operation of mixing, the outlet from the mixing tank is located at the bottom of the mixing tank, as at 6 and communicates through a vertical conduit 6 with an opening f at the level of the upper part of the mixing tank 6. Through the opening 7 the thoroughly mixed slurry overflows into the storage tank 7, which may be placed on the same level with the mixing tank.

The storage tank is of suitable capacity and may be provided with a traveling agitating device, which may comprise agitators F, f supported by a carrier f which is made to travel to and fro above the tank.

At a suitable point the tank f may be connected, as at g, with a pump 9 by which the slurry can be raised to a box 9 to be delivered thence to the kilns, the excess of slurry being returned from the box through a pipe 9 to the storage tank 7.

The pump g may also be connected, as by a. pipe 9 with the mixing tank 6 so that the slurry can be drawn directly from the tank e when conditions, such, for example, as the necessity for repair of the agitating devices in the tank 7, render it desirable to deliver slurry to the kilns directly from the tank 6 rather than from the tank f.

It will be understood that the slurry, as it is delivered from the grinders, is retained in the several receiving tanks to permit the composition of the slurry in each tank to be determined, then flows by gravity into the mixing tank in such proportions from the several receiving tanks as may be necessary to secure the correct composition of the mixture, and then overflows from the continuously filled mixing tank into the storage tank from which it may be delivered eventually to the kilns by a pump.

I claim as my invention 2- 1. Apparatus for mixing slurry comprising a plurality of receiving tanks, a single mixing tank ata lower level, means to deliver the slurry from the receiving tanks at will into the mixing tank, a storage tank, and a conduit communicating at its lower end with the mixing tank at the bottom thereof and having at the level of the top of the mixing tank an outlet through which the slurry is discharged by gravity into the storage tank.

2. Apparatus for mixing slurry comprising a plurality of receiving tanks, a common mixing tank at a lower level than the receiving tanks, means to discharge slurry from the receiving tanks at will into the mixing tank, a storage tank, means to deliver slurry from the bottom of the mixing tank at the level of the top or the mixing tank into the storage tank and a conduit communicating at its lower end with the bottom of the mixing tank and having at the level of the top of the mixing tank an outlet for discharge of the slurry by gravity into the storage tank.

3. Apparatus for mixing slurry comprising a plurality of receiving tanks, a common mixing tank at a lower level than the receiving tanks, means to discharge slurry from the receiving tanks at will into the mixing tank, a storage tank on the same level with the mixing tank, means to deliver slurry from the bottom of the mixing tank at the level of the top of the mixing tank into the storage tank, and a conduit communicating at its lower end with the bottom of the mixing tank and having at the level of the top of the mixing tank an outlet ior discharge of the slurry by gravity into the storage tank.

This specification signed this 1st August A. D. 1924.

POVL T. LINDI-IARD.

day of BEST AVAILABLE COPY Certificate of Correction.

It is hereby certified that the name of the assignee in Letters Patent No. 1,587,533, "ranted June 8, 1926, upon the application of Povl T. Lindhard, of Brooklyn, New ork, for an improvement in Mixing Slurry, was erroneously written and printed as F. L. Smith & Co. Whereas said name should have been Written and printed as F. L. Smidth (f0 00., as shown by the records ofassignments in this oflice; and that the said Letters Patent should be read with this correction therein that the same may conform to the record o f the case in the Patent Office. Signed andflsealed this 10th day of August, A. D. 1926.

[SEAL] A M. J. MOORE,

; Acting Gowwnissioner of Patents.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,587,583, granted June 8, 1926, upon the application of Povl T. Lindharol, of Brooklyn, New York, for an improvement in Mixing Slurry, errors appear in the printed specification requiring correction as follows: Page 1, lines 12 and 13, for the Word line read lime; and that the said Letters Patent should be read with these corrections therein that the same mag conform to the record of the case in the Patent Office.

igned and sealed. this 13th day of July, A. D. 1926.

[SEAL] M. J. MOORE,

Acting Commissioner of Patents. 

